N = int(input())
X = list(sorted(list(set(map(int, input().split())))))
if len(X) <= 1:
    print(0)
    exit(0)
ANSWER = X[1] - X[0]
for I in range(len(X) - 1):
    ANSWER = min(ANSWER, X[I + 1] - X[I])
print(ANSWER)